NASA documnetary detailing the events surrounding the loss of OV-099, Space Shuttle Challenger, shortly after the launch of the 25th flight of the Space Transportation System, Mission STS-51L, on 28 January, 1986, and the subsequent investigation into the loss of the vehicle and its crew of seven. The investigation shows that the Solid Rocket Booster field joints were of an insufficiently fault-tolerant design and when the vehicle was launched at below-normal temperatures, hot exhaust gasses leaked on ignition, damaging the integrity of the field joint, leading to a breach in the external tank and destruction of the orbiter.